[5p-C17-1~17] 13.8 Compound and power electron devices and process technology

[5p-C17-9] Temperature effect on time-dependent dielectric breakdown of atomic-layer-deposition Al₂O₃ films formed on GaN

〇Atsushi Hiraiwa^1,2, Toshio Sasaki¹, Satoshi Okubo³, Hiroshi Kawarada^1,3,4 (1.Waseda Univ., RONL, 2.Nagoya Univ., IMaSS, 3.Waseda Univ., FSE, 4.Waseda Univ., KMLMST)

Keywords:Al2O3, ALD, TDDB

We comparatively investigated TDDB characteristics of Al₂O₃ films formed under various ALD conditions. At room temperature, the TDDB lifetime of the films formed using O₃ as oxidant outperforms the lifetime of H₂O-grown films. By contrast, at 200ºC or higher, the lifetime of the O₃-grown films markedly decreases, underperforming the other. Therefore, although they allow a relatively large leakage current, H₂O-grown films are more suitable for power device applications. A remaining challenge for the H₂O-grown films is to enhance their TDDB lifetime, which is projected to be 20 years under a rated voltage (equivalent SiO₂ field of 4 MV/cm) at 200ºC.